Adds more platform enum constants.

Moodle 2.1 to 2.4 still use the same connector but now each has its own constant for unambiguous configuration.
Disable Moodle 2.1, 2.2

Needs more thorough testing.
Refactor Moodle connector naming
Improve localhost access restriction
Fix localhost access restriction

Multiple valves don't work. Adds IPv6 scope % and ::1.
Load version from properties file

Fixes LemoProject/Lemo-Application-Server#6
`pom.xml` isn't available in tomcat. Use a Maven replacement variable in `lemo.properties` to add the `lemo.version` property value.
- changed log-level to "info"
- fixed problems with renamed moodle19 conn
- updated lemo.xml
Exception handling, documentation
Documentation
Adds course id filter example and logging
Merge branch 'develop' of https://github.com/LemoProject/Lemo-Data-Management-Server into develop

Conflicts:
	src/main/resources/lemo.xml
Merge branch 'develop'